Device for creating an illusion



Feb. 18, 1936. R HVARDme, JR u 2,030,919

DEVICE FOR CREATING AN ILLUSION OrzLginal Filed Dec. 4, 1931 3 Sheets-Sheet l :Z BY

ATTORNEY Feb. 18, 1936.l RI HARDlNG, JR

DEVICE FOR'GREATING AN ILLUSION Original Filed Dec. 4. 1931 3 Sheets-Sheet 2 ATTORNEY Feb. 18, 1936. R. HARDING, JR 2,030,919

DEVICE FOR CREATING AN ILLUSION Original Filed Dect 4, 1931 3 Sheets-Sheet 3 yBY ATTORNEY Patented Feb. 18, 1936 UNITED STATES DEVICE Foa cnEA'mNG AN ILLUSIoN nobel-s ns1-ding, Jr., Elmsford, N. Y., assignmto Sirlan Lamp Company, Newark, N. J., a corporation of Delaware Application December 4, 1931, serial No. 578,918

Renewed July 9, 1995 3Claims.

This invention relates to display devices and especially to such devices adapted to create the illusion of motion or to give stereoscopic etl'ects.

One of the objects of the invention is to provide -a device for producing such effects without moving parts.

Another object of the invention is to provide a vdevice for creating illusional eil'ects as of motion or stereoscopic eects which has a plurality of light sources with means to cause each source to ash intermittently and out of phase with another source.

Anotherobject of the invention is to produce various illusions of motion with the aid of colors.

Other objects of the invention and objects relating particularly to the construction and assembly of the various parts will be apparent as the description of the invention proceeds.

The invention'has Abeen illustrated in the accompanying drawings in which Fig. 1 is a front elevational view of a lamp which may be used with the device:

Figs. 2, 3, and 4 are enlarged fragmentary views of several embodiments of the electron emitting element shown lin Fig. 1;

. used in another embodiment oi the invention showing the manner of connecting the lamps in the circuit. y

, In the application of Chester H. Braselton entitled Electrical discharge device, led June 3,

i 1930, Serial No. 459,048, a lighting device is shown and described which comprises a fllamentary wire which is rendered electron emitting in the presence of an inert gas having a certain pressure which may vary with the voltage used and the eifect desired. The heating of the lament appears to cause ionization of the gas in the immediate vicinity of the illament rendering it conductive and. forming a halo of lighted gas around the lament which gives od an intense illumination. The halo thus formed is responsive to variations of voltage and follows the alternating cycle, collapsing and expanding again as the direction of the voltage changes. The halo may also be made to expand at will by providing a conductor in the vicinity thereof and having a variable potential. When the potential is made negative the halo collapses while if it is increased in potential towards the positive side the halo will be caused to expand. 'I'his forms the subject matter of the application filed by Samuel 5 Ruben entitled Apparatus for producing and modulating an ionic discharge, Serial No. 471,- 977, illed July 3 1, 1930. The present invention intends to make use of these principles as will be hereinafter explained.

Referring now more speciiically to the drawings the lamp as described in the first mentioned application above may comprise an envelope III which is formed integral with the usual press I.I for supporting the elements. A pair of electron emitting elements I2 and I3 may be supported at their lower ends respectively upon support rods Il and I5 which are sealed in the press II and at their upper ends upon a cross connecting member I6 which maybe welded or otherwise 20 attached to'an upright I'I which may extend down the center of the bulb and be sealed in the -press II between the supports I4 and I5. Leading-in wires I8 vand I9 may be connected respectively to the support rods I4 and I5 for making 25 the electrical' connections outside of the bulb and a suitable base (not shown) may be attached in the ordinary well known manner. 'I'he electron emitting elements I2 and I3 may each comprise a coll 2|! of wire, preferably a refractory 30 resistance wire such as tungsten, molybdenum, tantalum, nichrome, and may be coated as shown in Fig. 2 with electron emitting material 2I which may be any of the well known materials used for that purpose such as the oxides of the alkaline earth metals or mixtures of such oxides held together with a suitablebinder. If desired the emitting material may contain a material which also has the property of selective radiation such ascalcium oxide.

In Fig. 3 a modified form of the electron emitting element is shown in which the coil 22 has a core 23 of the electron emitting material extending. down through the center and in contact with at least a portion thereof and in Fig. 4 a still further embodiment is shown wherein the coil 24 is coated with a thin layer of electron emitting material so that the individual turns are coated separately and are spaced apart from each 50 other. Other forms of electron emitting elements may be used such as a filament wire with the material incorporated in the metal itself as the well known thoriated tungsten filament which may be made by treating tungstic acid and thori- 55 uncoiled illament may.

ends of the lament, the small coils 20a may be -placed at each end of each of the elements and attached to the support rods. These coils may be made of wire capable of standing a high temperature about the same diameter as the wire of the lament coil. They should not be so large however as to cool the end 'of the iilament too much but they should be large enough to carry the additional. current. They may or may not be coated with the emitting material.

The envelope or bulb I0 may be filled with an inert gas which may preferably be one or more of the monatomic gases such as argon, neon, helium, krypton, or xenon, at a pressure in the neighborhood of 200 mm. of mercury depending on the voltage used and the desired size of the halo as greater pressures tend to cause the halo to be confined more closely to the filament. Also if desired to produce certain color eifects as will be hereinafter described or increase the conductivity of the gas certain metal vapors, such as the vapors of mercury, caesi'um, calcium, rubidium, or cadmium may be used in small quantities mixed with` the gas. kThese vapors may be introduced by providing a, small container 26 having a pin hole 21 therein and supported by means of a wire 28 upon one of the support rods, as the rod I5. Inside of the container I provide a small piece of magnesium or calcium and a salt, such as a chloride, of the metal or metals whose vapor is desired to be placed in the bulb. After the bulb is sealed 01T the container 26 m-ay be heated as by external bombardment which causes the magnesium or calcium to unite with the salt forming magnesium or calcium chloride and liberating the free metals which condense on the walls of the bulb to be vaporized again when the lamp is heated in use.

With the elements mounted as shown in Fig. 1 the envelope l0 may be connected to an exhaust pump in the usual manner and an oven placed over it to raise the temperature to between 350 to 400 C. or to as high a temperature as the glass will stand without deforming. A current may be run through the lament at this time to raise it to about 600,o C. to drive out lthe occluded gases which may be present. When lno more gas appears to be in the bulb as is evidenced by the lack of fluorescence when high tension current is directed against the walls of the bulb from an induction coil the current may be increased in the lament -to raise it to about 800 C.

to drive out the binder from the electron emitting material. When no more gas again appears to be in the bulb the current may be still' further increased to about 1200 C. for a moment, the pump being connected all this timeto remove all the gases driven oi. Then the oven may be raised, the lament current turned off, the pump disconnected, and a slight amount of an inert gas such as neon'at about 1/2 mm. pressure may be admitted to the bulb and the filament current turned on again and gradually increased. Spots of localized discharge will then appear having a reddish color. These spots gradually spread until a diffused glow completely fills the bulb which appears to activate the electron emitting coating and should be maintained until a uniform discharge is had throughout thebulb which should take less than ten minutes. During this time the current should not be raised too high on the iilamentso as not to throw oif or destroy the coating. If white discharge spots appear on the filament or support rods it is an indication that there aremore gases or vapors within the bulb and the bulb. should again be exhausted and the whole process of activation repeated.A

When the activation is completed the filament temperature may be raised for a. moment to about 1400 C. and then a vacuum pump again connected and the gas pumped out to remove any undesirable gases which may have been driven oi during' the activation process. When a high vacuum in the neighborhood of .5 micron is again obtained the filament current may be disconnected, the pump turned off, and about 50 mm. of neon gas followed with about l5 0 mm. of argon gas may be admitted to the bulb and the bulb sealed oil.

If .the metal vapors are desired in the bulb the container 2G may then be heated by external bombardment to flash the magnesium or calcium and in any case it may be preferable to have the magnesium or calcium in the container to clean upthe gases afte'rsealing olf. The bulb is then ready for use.

In Fig. 5 the apparatus for producing the illusion is shown diagrammatically. Here the lamps 29 and 30 corresponding to what has just been describedare mounted in two projection boxes 3| and 32 respectively provided lrespectively with reflectors 33 and 34 vand optical systems 35 and' 3G forv throwing an image upon a'screen 31. A transparent plate 38 having an object thereon is placed between the lamp 29 and the optical system 35 so that the image of the object on the plate 38 is thrown upon the screen 31. Also a 'w transparent plate .39 carrying an object is positioned between the lamp 30 and the optical sys-v tem 36 to throw the image of the object on the plate 39Vupon the screen 31.

The lamp 29 may be connectedjdirectly across.

of the lighting circuit by means of a wire 43, theY other side being connected by means of a wire 44 to an inductance 45 which is in turn connected 4by means of a wire 46 to the other side of the -lighting circuit, The inductance 45 is made of such a value that the voltage of the lamp 30 will'be out of phase with the voltage of the lamp 29 so that the lamps will ilicker alternately.

For purposes-of illustration I haveshown the two plates 38 and 39 in Fig. 6 having the image of a wheel 41 thereon. The plate 38 shows the wheel with the spokes in vertical and horizontal f planes while the plate 39 shows the spokes in planes at an angle to the horizontal and vertical. The projection devices 3| and 32 are so arranged at an angle that the two images of the wheel 41 on both plates 38 and 39 are superimposed on the screen 31 and inasmuchI as the two lamps 29 and 30 produce light alternately the picture of the Wheel 41 on the plate ,38 Will be alternated with a picture of the wheel on the plate 39 and inasmuch as the wheel on the plate 39 is rotated slightly with respect to the wheel on the plate 3B the effect of the alternation will cause an appearance of rotation of the wheel.

As stated above the introduction of metaLvapors in the bulb will produce colored eiects. Thus a red light may be produced with a relatively large amount of neon gas with a trace of rubidium vapor, while a yellow light may be produced with a'relatively large amount oi' neon gas and mercury and caesium vapor. A blue light may be provided with argon gas and a small amount of mercury vapor and a small amount of rubidium vapor while mercury vapor with argon gas will produce the lower wave length light as the violet'.

The apparatus illustrated in Figs. 7 and 8 is adapted to make use of two lamp bulbs 48 and 48 each producing light of a diil'erent color as for instance the lamp 48 giving a red light while the lamp 48 gives a yellow light. These two lamps are placed in a housing 50 provided with a suitable reector 5I, and a transparent plate 52 is positioned in front of them. The plate 52 may have an object printed thereupon, as the wheel 58. Ii the spokes 54 oi the wheel which are shown in solid lines are colored red and the spokes 55 which are shown in .dotted lines are colored yellow the red spokes will appear when the yellow light is lit and the yellow spokes will become apparent when the red light islit therefore giving the same eilect as the apparatus oi! Figs. 5 and 6 but the image is on a single plate 52 which is viewed by the observer. Various colors oi course may be used and any desired color eilect may be obtained in this manner.

Another'embodiment of the invention is illustrated in Fig. 9 in which the principles described in the Ruben application above referred to are used. The two bulbs 58 and 51 of this iigure are exactly alike and hence only one will be described. The bulb 38 comprises the usual envelope sealed onto a press 58 for supporting the elements. A single electron emitting element 58 is shown supported at its lower end upon a support rod 88 which is sealed in the press and at its upper end upon a support rod 8| which extends rearwardly and is bent downwardly to be also-sealed in the press 58. A helical grid 82 surounds the element 58 and may be supported upon a wire rod 83` which may be supported at its lower end upon a support rod 84 sealed in the press and at its upper end upon a support rod 85 which may be sealed in a glass bead 88 mounted on the support rod 8i and supporting the grid out of contact with the element 59. Leading-in wires 81, 88, and 88 may be connected respectively to the support rods 80, 84, and 8|. The leading-in wire 81 may bev connected to one side 10 of a lighting circuit while the leading-in wire 88 which is attached to the other end of the lament may be connected tothe other side 1i of the circuit. The leading-in wire 88 may be connected as shown to the leading-in w'lre 81 thus connecting the grid 82 to the lower end of the element or to the side 10 of the lighting circuit. The lamp 51 may have its leading-in wire 81 connected to the side 1I oi the lighting circuit while the opposite end of the iilament may be connected to the side 18 of the circuit by the leading in wire 88, or just the reverse of the connections for the lamp 88.

Thus connected the two lamps 56 and 51 of Fig. 9 may be used with either of the devices shown in Figs. 5 and 7. In the latter case, of course, the lamps would be provided with difierent combinations of gases to vary the color eil'ects thereof. When the grid 82 of one lamp is made negative the halo around the element tends to collapse and when it becomes positive the tendency is to increase the size of the halo'. When the wire 10 is positive and the wire 1l is negative, which is the case for one cycle of the alternating current we ve, the grid 82 of the lamp 51' will be negative with respect to the main portion of the iilament 59 and -hence the halo in that lamp tends to collapse while at the same instantl the grid oi' the lamp 58 is positive with respect to the main portion of the lament and hence the h'alo tends to increase in that lamp. When the potential is reversed and the wire 10 becomes negative and the wire 1I positive the halo will be increased in the lamp 51 as the grid is more positive than the illament, while in the lamp 58 the halo is decreased because the grid is more negative than the lament. 'I'hus in an ordinary alternating current cycle the lamps will be made to dicker, one lamp being lighted for one-halt cycle and the other being lighted for the other half.

While I have illustrated the invention in connection with a picture of a wheel and shown how the wheel appears to rotate due to the operation of the lamp it is evident that other forms oi motion may be simulated thus a ilame, or smoke, or the movement of water may be made to appear very realistic.v Also a stereoscopic effect may be obtained if desired by producing two images one taken from a slightly diierent angle than the other.

If desired the whole apparatus may be made very small so that it may be placed in a single rhousing including the screen 31 in Fig, 5 or in either case the apparatus may be made to project on a screen some distance away. In the case of Fig. '7 where this is desired separate projection systems should be used for each lamp 48 and 49 and the objects may be printed or otherwise placed upon the screen through which the lights are projected alternately.

Many other modifications may be resorted to without departing from the spirit of the invention and -I do not desire to limit myself to what has been shown and described except as such limitations occur in the appended claims.

What I desire to claim and secure by Letters Patent is:

i. In a device of the class described a pair of electriclamps each comprising an envelope, a illamentary resistance wire within said envelope,d electron emitting material in contact with said wire, and an inert gas having a pressure in the neighborhood of 200 mm. of mercury surrounding Said wire, means to minimize the ionization oi' the gas around said filament when the current flows in one direction through the lamp; means to connect said lamps reversely to said circuit so that when the current flows in one direction the ionization of gas in one lamp is minimized while when the current flows in the other direction the ionization of gas in the other lamp is minimized. a pair of objects one adapted to receive the light from each oi said lamps. a screen, and means to project said objects in superimposed position upon said screen.

2. In a device of the class described a plurality of electric lamps, each of said lamps comprising an envelope, a iilamentary resistance wire within said envelope, electron emitting material in contact with said wire, an inert gas surrounding said Wire and having a pressure in the neighborhood of 200 mm. of mercury, one of said lamps having a` trace of a metal vapor' within said envelope which will produce a certain color, the

v other of said lamps having another metal vapor in said envelope which will produce a different color, means to connect said lamps to an electric light circuit whereby said lamps alternately radiate light, a pair of stationary objects positioned to receive the light from each of said lamps,l one 4 2,oao,919

o! said objects being invisible in one light and the other being invisible in the other light, and means to project said objects upon a screen in superimposed relation.

3. In a device of the class described a pair of electric lamps each comprising an envelope, a lamentary resistance wire within said envelope, electron emitting material in contact with said wire, and an inert gas surrounding said wire, means to minimize the ionization of the gas around said lament when the current flows in one direction through the lamp, means to connect said lamps reversely to said circuit so that when the current ilows in one direction the ionization of gas in one lamp is minimized while when the current ows in the other direction the ionization of gas in the other lamp is minimized, a pair of objects one adapted to receive the light from each oi'said lamps, a screen, and means to project the images oi.' said objects in superimposed position upon said screen. e

ROBERT HARDING, Jn. 

